Within the top left-hand quarter of a square(its side an integer below 40 cm) I marked two points, each of which was distant an integral number of cm, not only from each side of the square but also from both the top left-hand corner and the bottom right-hand corner of the square.

What size was a side of this square?

Based on Enigma problem (New Scientist 2010)

(In reply to

can't be sure by Charlie)

** **I stand corrected.

It should be declared:

** side = ODD** integer .

Btw , it is solvable analytically.

Thanks for your correction.